Flexible shaft-coupling



W. R. FOX AND A. A. RIDDELL.

FLEXIBLE SHAFT poUmuc. I APPLICATION FILE'D- DEC. 10. 1919.- I

' Patented June 28, 1921.

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UNITED STATES WILLIAM 3. FOX AUSTIN RIDDEIJL, OF JACKSON, ASSIGNOR TOSAID FOX. I

PATENT OFFICE.

MIGHIGA'FT; SAID RIDDELL FLEXIBLE SHAFT-COUPLIN G.

Specification of LettersIatent. Patent d J 192 Application filedDecember 10, 1919. Serial No. 343,771.

. fication.

The invention relatesto that type of flexible shaft coupling in which apair of forks are connected to a central block by pins which form thepivots aboutwhich the forks move, these-forks being arranged a quarterturn relative to each other. n this type of joint, where the pins areinserted into or-through the block, and screws or other means areemployed to hold the parts together, or where each fork or the block ismade in sections, an objection exists because of the liability of thepins Or other members to work loose, due to stresses and wear, resultingin imperfect transmission of power, or eventually to disruption of theshaft.

One object of the invention is to provide a coupling in which the parts,11. 6., the block, pivot pins and fork, will be connected in a manner topermit them to function perfectly in'assuming the necessary differentrelative positions, but the connection.

will be such that the parts will network out of place or' work loose anddetach one from the other, because they are permanently attached in thesense that while they can have the necessary relative movement,

they are so assembled and interlocked that only by direct breakage cantheybe separated. They cannot' work apart and drop away'the one from theother.

Other objects of the invention will appearhereinafter. a

In the accompanying drawings:

Figure 1 is a side view of a joint embodyin certain features of myinvention.

Fig. 2 is a'longitudinal'sectional view of Fig. 1 but with the pinsunited to each other and to the block by welding or brazing.

Fig. 3 is a view of the center block detached.

Fig. 4 is asectional viewof the block on line 4-4 of Fig. 3.

Fig. 5 is a sectionalview through the block with the pivot pinsassembled there- -plaI,1e in these pins,

with, these pins having mitered inner ends as in Figs. 1 and 2. c

Fig, 5 a side view looking frbm the same directlon as in Fig. 5.

5 is a plan view of Fig. 5.

Figs. 6, 6 'and 6* are views similar to Figs. 5 5? 5 but with pins whoseinner contacting ends mstead of being mitered to fittogether are ofconical shape.

Fig. 7 is a view of a modification showing shouldered pins.

8 is a cross section of-Fi 7.

Fig. 9 is .a view of a modification in which one long pin and two shortpins are employed instead of four pins.

F1 10 is a cross section of Fig. 9, sub stantially on line 1010 of Fig.9 the short pins being shown inelevation.

F1g. '11 is a view of another modification in whlch three pins interlockand are self centering. 1

The center block 1 is formed in one piece with a cylindrical opening 2running all the way, or only part way, through it, and with axiallyahned openings 3 to receive the pair of pins 3 and other axially alinedopenings as 3", to "receive the pins 3 which are arrangedin a plane atright angles to the which the pins 3 lie. These pin's meet at theirinner ends and substantial contact is afforded by forming these 'inner'ends mitered as in Figs. 5, to 5 or conical as in Figs. 6 to 6 The pinsare selid iecjes. The forks 4, 4 are'of one piece eac In assembling theparts the forks are placed 1n position a quarter turnjrelatively to eachother, with their openings 4 and P in axial alinement with the properpair of openings in the block and then the pins 3, 3' are insertedthrough the block with their inner ends meeting at or electricweldingthese inner ends together and to the block, the pins become-ineffect integral parts of the block and as the fork, projecting ends ofarms are on the outer theparts of the coupling. are permanently movementof the forks is allowed. For

electric welding or brazing together the the forkarms and into heldtogether, though relative .the center 6f the block," and then by brazinginner ends of the pins and brazing or weld- 7 ing them to the block,access thereto is af- 2 of the block forded by the central openingcenter of the contributes to quantity production because the same pincan be assembled in any one of the openings in the block and the forkscan be assembled with the block in either of the two possible positionswithout special attention or selection on the part of the workman.

It is important that the rubbing surfaces of the block, forks and pinsbe hard and smooth. By the present improvement it is possible to hardenthe'parts after they are put together so that hard contacting surfacesare provided.

The parts may be made of tool steel. After the brazing or welding of thepins and center block, the coupling is raised to the proper temperatureand the-n cooled which hardens them and then the temper is drawn.

to the proper point for working. The same result can be obtained byusing low carbon steel as the parts have been properly machined and packhardened which carbonizes them, and as they are welded or brazed theycan be raised to the proper temperature and then cooled, which willharden the surfaces where they'come in contact, the pins with the workand the block with the fork. In the drawing, the hard working surface isindi cated at 3 and the soft center at a.

If desired the pins may be headed as shown at w and the forkarms can beformed each with a countersunk recess to receive the heads of the pins.In the twisting action of a universal joint long use will produce suchwear that the forks will have a tendency to spread, but this will beovercome by the pins connected together and to the block at their innerends and having the heads overlying parts of the fork arms.

While the brazing or welding, as carried outin accordance with thepreceding description, results in connecting the inner ends of the pinsto each other and. also to the block it is conceivable that the pins maybe welded to the block at their inner ends and not to each other or themay be welded to each other withoutreference to the degree ofweld to theblock. if any, but the welding of the pins. both to each other and tothe block, makes a strong integral construction,

' which may be carried out with the simplest form of procedure, and thisis preferred.

Figs- 7 and 8 show the p ns provided with shouldersz'i. These are shownin these views in their original condition, they are brazed together.will add to the security of the fastening when the brazing is done, themetal flowing into? the space around the neck of the pin above theshoulder and forming substantially an integral locking connection atthis point.

The parts of the coupling can be hardened at the time of welding orbrazing or at a separate operation.

In the brazing or welding operation one fork member may be turned asideat right angles to the other to expose the center block for placing thetool or electrode. In brazing, the'torch will heat up the center-blockand the pins and when they have reached the proper temperature, theborax and brass, or bronze, is introduced and the brazing thuscompleted.

Both sides of the center block may be that is, before- The shouldersbrought under the brazing torch or electric 'arc'so as to insure a morepositive uniting of the parts. For brazing one side of the block mayhave the hole leading to the center while the other side may be leftintact, i. 6. without an opening. I

The brazing may be done by heating to the proper degree in a furnace,having previously introduced the brazing compound-into the open side ofthe block.

In Figs. 9 and 10 I show a modification of the pin arrangement in" whicha long pin 3 is used and two short pins 3, the inner ends of which bearon t-he long pin to be brazed or welded in place.

In Fig. 11 another modification is shown in which the long pin hassockets or openings 6 to receive dowels 7 on the short pins which can bebrazed.

This will facilitate the quick and accurate assembly of the pins,because only three pins need be handled instead of four, and furthermorethe dowel and sockets definitely determine the relative position of thepins to each other. When one of the short pins finds its socket in thelong pins these two members are in their desired positions with theirends projecting beyond the center block to afford proper pivot bearingsfor the forks. and of course the other accurately positioned merely byinserting it. The above advantage is also present in Figs. 7 and 8.

This self centering feature is also present in the forms of Figs. 5 and6 where the four pins are specially formed at their inner ends to haveself determination as to their positions.

If the four pins were cut off square they would not center themselvesnor would they readily maintain their relative positions it oncecentered. These pins may be said to be interengaged because the end ofone, where four are used, fits in the space or recess short pin will bewould be within the purview of my inven-- of said members.

formed between the ends of two others, or where three are usedthe endsof two fit in the recesses formed in the lon pin.

It will be understood that w ere in the appended claims I refer to thepins as being fastened by brazing at their inner ends this language isto be construed in' a general sense applicable to both formsof theinvention whether there be three pins or four. In the case of the singlelong in this in one aspect is two pins combined wlth their inner endsuinted to each other and-to the other pins, one outer end forming onepivot and the other outer end the other pivo One broad feature of theinvention is-the assembly of the two members, i. e. the one piece forksand the center block in proper relative positions with their pivotopenings in alinement, then inserting the pivot pins brazing the pins toone and then welding or of the said members. c

In carrying out the invention in the specific way described the brazingor welding action takes place upon all of the pins at once at theirinner portions exposed within the block. If the pins were welded to theforks after being inserted four separate welds 0r brazing points wouldexist, one at the outer portion of each pin where it rests in the fork,but despite thisthe latter'way tion.

I claim: 1 In combination, the members, z. e. the one piece forks andthe center block, ins welded or .brazed to one of said mem ers andextending into and turning in the other 2. A flexible shaft couplingcomprisin a block, pins having their inner ends wel ed or brazedtogether within the block, and

I forks pivoted on the pins, substantially as described.

3. A flexible shaft coupling comprising a block, pins set therein' andwelded or brazed thereto at their inner ends within the block and forkspivoted on the pins.

4. A flexible shaft coupling comprising a 5 block, pins set therein andwelded or brazed (pins extending through to each other and to the blockat their inner ends within the the pins, substantially as described.

'5'."In combination a hollow block having its wall and exposed at theirinner endswithin the block for being fastened by welding or brazing andforks pivotally mounted on the pins,

.. 6. In combination a block having pins inserted through its wall andwelded through the open end oftheblock, and forkspivoted on-the pins,substantially as described. t

In'combination a block, pins settherein and having their inner endstapered 'or mitered and in contact and forks pivoted on positioning,

ing metal to hold block, and forks pivoted on 9. In combination a centerblock, forks embracing the same, and pins inserted through the forksinto the block and having interengaging formations at their adj acentinner said pins being held by brazing or welding at their inner ends.

10. In combination, a center block, forks embracing the same, four pinsinserted through the forks into the. block and having inter-engagingformations at, their adjacent inner ends whereby they'are. selfpositioning, said pins being held by-brazing or welding to one ofthemembers, forks or center block, and turning in the other member,substantially as described. I

- 11-. A flexible shaft coupling comprising a block, one piece forksembracing the block and pins, of like diameter inserted in the forks andblock and held at their inner ends by brazing or welding within theblock, substantially as described.

12. In a shaft coupling, the combination of a hollow block, pinsfurnishing pivots for forks having shouldered ends within the blocks toprovide means for receiving brazthe pins in place.

13. In combination a block, a pair of forks, pins having heads at theirouter ends bearing on the forks, said pins being welded or brazed at thecenter of the block, substaning a flexible coupling for s afting'consisting in first positioning the forks in relation to the connectingblock, then inserting the pivot pins into the block through the forksand then uniting theinner ends of the pins to the block, by welding orbrazing, substantially as described;

16. The herein-described procew of making a flexible coupling forshafting'consisting in first positioning the forks in relation to theconnecting block, then inserting the pivot pins into the block throughthe forks and then uniting the inner ends of the pins by welding orbrazing, substantially as de- 17. The herein-described rocess of makinga flexible coupling for s afting consistportions whereby they are selfproper relation, then insert through the forks mto ing in firstpositioning the forks in relation 3 to the connecting block, theninserting the pivot pins into the block through and then securing theinner ends 0 f the pins 1 5 by welding, and hardening the contactingsurfaces of the fork and pins and fork and I block after assembly ofsaid parts, substantially as described.

18. The herein-described process consist- 10 ing in placing the forks inrelation to the.

the forks connecting, block, then inserting the pivot pins through thefork into the block and affixing in place by brazing or welding and thenhardening the contacting wearing surfaces of the parts, substantially asdescribed.

In testimony whereof, we aflix our signatures.

WILLIAM E. FOX. AUSTIN A. RIDDELL.

